GPW, a tool for comparing harvests.

[The Stoned Jester]

Damn where'd you find that picture thought I deleted that one

[Naycha]

 

Something I found interesting was the actual power my ballasts used when connected up to a device that measures power usage. It was a while ago but I think my 600 watt digital growlush ballast would draw around 618 watts.

[louise]

Don't worry about the juvenile behaviour Nay, mention maths of any sort and they switch their brains off.

 

That is a good point, calculating the actual power draw of lamp (and including the power used by fans) would lead to more accurate calculations.

[Sir PsychoHashy]

Sorta thanks Lou, unfortunately that put downward pressure on my perceived results  

 

It does make the term more meaningful and useful as a personal benchmark and return on cost though, so genuinely thanks for putting that up .  Probably not what most people on forums use to get the figures they post though.  Probably not a great tool to compare to other peoples grows as it puts many variables into the equation, a big one being my habit of doing an extra long flower compared to others who like to harvest at a much earlier stage. 

 

I just got 0.67/w from my last grow, and now have no idea whether that's good, bad, or okay given I went for over maturation?  Would be curious to know what average benchmarks should be using this method, and what sort of variation should be expected for longer, or shorter, flowering times.  Could make sativa growers feel inadequate otherwise

[louise]

Can't see why you think it's a problem? The grower who harvests early uses less energy, but the grower who harvests later cuts a heavier harvest.

[Sir PsychoHashy]

Nah, don't see it as a problem Lou, just wondering what sort of benchmarks would be considered average for the different timings.  Would agree that up to a point later harvests increase yield, but in my limited experience that last couple of weeks of maturation that I go for don't seem to make any difference to the size of the buds, that is getting into the extreme end though.

[The Hash Nibbler]

GPW is just a real rough tool to work out light in for product out.

It does not use variables and only really was a commercial tool.

All one strain... all same lighting... over same flower period.

Is still a good tool for guaging a grows success.

In the end if your happy... it doesnt matter.

 

1g a watt is the optimum in most circumstances where its just lights and plants in soil or grow medium.

Have seen more in DWC and grows with CO2.

 

I think .75g per watt is pretty good and anything else is a bonus.

Personally I pushed for as close to 1g per watt as possible.

Just because it makes you look at what you could do/ change to get a better yield

. Doesnt mean you cant grow..... just that maybe you could brush up on a few things.

 

I grew multiple strain grows so think that is harder to average, as every strain yields differently.

 

Just a simple case of... if you put all that effort in and take the risks....then you want a good result in return and a rough way to figure if its good, bad or ugly.

 

A successful / safe growth should be its own reward regardless of yield.

 

Hops.

[louise]

It does not use variables....

Thank you Nibbler for contributing and showing us how much you understand about statistics... the variables in the formula are time, wattage, light cycle and harvest weight in grams.

 

I made this post to clear the confusion that seemed to exist over what calculations were actually involved in calculating the gpw... and as that has been achieved, I will close it and prevent anymore puerile comments.